This application claims priority to U.S. Provisional Application No. 61/302,324, which is incorporated herein by reference in its entirety.
RANTES, which is an abbreviation for Regulated upon Activation, Normal T-cell Expressed, and Secreted, is an 8 kDa protein classified as a chemotactic cytokine or chemokine, RANTES was identified as a gene expressed several days following T cell activation. A CC chemokine, RANTES, which has been found to be expressed many human diseases, is regulated in T lymphocytes by Kruppel like factor 13 (KLF13).
RANTES, which interacts with chemokine receptors CCR3, CCR5 and CCR1, is chemotactic for T cells, eosinophils, and basophils. It is involved in the recruitment of leukocytes into inflammatory sites. The combination of RANTES with cytokines IL-2 and IFN-γ, which are released by T cells, induces the proliferation and activation of certain natural-killer (NK) cells. Such cells are referred to as CHAK (CC-Chemokine-activated killer) cells.
U.S. application Ser. No. 09/622,452, which is incorporated herein by reference, discloses compositions and methods of using nucleic acid molecules that encode RANTES as immunotherapeutics and vaccines components. The expression of RANTES when used as an immunotherapeutic modifies certain aspects of the immune system in the individual in whom it is expressed. Similarly, expression of RANTES when used as part of a vaccine enhances certain aspects of the immune response against the vaccine immunogen.
Immunotherapy refers to modulating a person's immune responses to impart a desirable therapeutic effect. Immunotherapeutics refer to those compositions which, when administered to an individual, modulate the individual's immune system sufficient to ultimately decrease symptoms which are associated with undesirable immune responses or to ultimately alleviate symptoms by increasing desirable immune responses. In some cases, immunotherapy is part of a vaccination protocol in which the individual is administered a vaccine that exposes the individual to an immunogen against which the individual generates an immune response in such cases, the immunotherapeutic increases the immune response and/or selectively enhances a portion of the immune response (such as the cellular arm or the humoral arm) which is desirable to treat or prevent the particular condition, infection or disease.
Vaccine protocols can be improved by the delivery of agents that modulate a person's immune responses to induce an improved immune response. In some vaccination protocols in which the individual is administered a vaccine that exposes the individual to an immunogen against which the individual generates an immune response, an agent is provided that increases the immune response and/or selectively enhances a portion of the immune response (such as the cellular arm or the humoral arm) which is desirable to treat or prevent the particular condition, infection or disease.
Vaccines are useful to immunize individuals against target antigens such as allergens, pathogen antigens or antigens associated with cells involved in human diseases. Antigens associated with cells involved in human diseases include cancer-associated tumor antigens and antigens associated with cells involved in autoimmune diseases.
In designing such vaccines, it has been recognized that vaccines that produce the target antigen in cells of the vaccinated individual are effective in inducing the cellular arm of the immune system. Specifically, live attenuated vaccines, recombinant vaccines which use avirulent vectors and DNA vaccines each lead to the production of antigens in the cell of the vaccinated individual which results in induction of the cellular arm of the immune system. On the other hand, killed or inactivated vaccines, and sub-unit vaccines which comprise only proteins do not induce good cellular immune responses although they do induce an effective humoral response.
A cellular immune response is often necessary to provide protection against pathogen infection and to provide effective immune-mediated therapy for treatment of pathogen infection, cancer or autoimmune diseases. Accordingly, vaccines that produce the target antigen in cells of the vaccinated individual such as live attenuated vaccines, recombinant vaccines that use avirulent vectors and DNA vaccines are often preferred.
The direct administration of nucleic acid sequences to deliver proteins or vaccinate against animal and human diseases has been studied and much effort has focused on effective and efficient means of nucleic acid delivery in order to yield necessary expression of the therapeutic/adjuvant protein and/or desired antigens.
DNA vaccines have many conceptual advantages over more traditional gene delivery and vaccination methods, such as live attenuated viruses and recombinant protein-based vaccines. DNA vaccines are safe, stable, easily produced, and well tolerated in humans with preclinical trials indicating little evidence of plasmid integration [Martin, T., et al., Plasmid DNA malaria vaccine: the potential for genomic integration after intramuscular injection. Hum Gene Ther, 1999. 10(5): p. 759-68; Nichols, W. W., et al., Potential DNA vaccine integration into host cell genome. Ann NY Acad Sci, 1995. 772: p. 30-9]. In addition, DNA vaccines are well suited for repeated administration due to the fact that efficacy of the vaccine is not influenced by pre-existing antibody titers to the vector [Chattergoon, M., J. Boyer, and D. B. Weiner, Genetic immunization: a new era in vaccines and immune therapeutics. FASEB J, 1997. 11(10): p. 753-63]. However, one major obstacle for the clinical adoption of DNA vaccines has been a decrease in the platform's immunogenicity when moving to larger animals [Liu, M. A. and J. B. Ulmer, Human clinical trials of plasmid DNA vaccines. Adv Genet, 2005. 55: p. 25-40]. Recent technological advances in the engineering of DNA vaccine immunogen, such has codon optimization, RNA optimization and the addition of immunoglobulin leader sequences have improved expression and immunogenicity of DNA vaccines [Andre, S., et al., Increased immune response elicited by DNA vaccination with a synthetic gp120 sequence with optimized codon usage. J Virol, 1998. 72(2): p. 1497-503; Deml, L., et al., Multiple effects of codon usage optimization on expression and immunogenicity of DNA candidate vaccines encoding the human immunodeficiency virus type 1 Gag protein. J Virol, 2001. 75(22): p. 10991-1001; Laddy, D. J., et al., Immunogenicity of novel consensus-based DNA vaccines against avian influenza. Vaccine, 2007. 25(16): p. 2984-9; Frelin, L., et al., Codon optimization and mRNA amplification effectively enhances the immunogenicity of the hepatitis C virus nonstructural 3/4A gene. Gene Ther, 2004. 11(6): p. 522-33], as well as, recently developed technology in plasmid delivery systems such as electroporation [Hirao, L. A., et al., Intradermal/subcutaneous immunization by electroporation improves plasmid vaccine delivery and potency in pigs and rhesus macaques. Vaccine, 2008. 26(3): p. 440-8; Luckay, A., et al., Effect of plasmid DNA vaccine design and in vivo electroporation on the resulting vaccine-specific immune responses in rhesus macaques. J Virol, 2007. 81(10): p. 5257-69; Ahlen, G., et al., In vivo electroporation enhances the immunogenicity of hepatitis C virus nonstructural 3/4A DNA by increased local DNA uptake, protein expression, inflammation, and infiltration of CD3+ T cells. J Immunol, 2007. 179(7): p. 4741-53]. In addition, studies have suggested that the use of consensus immunogens can be able to increase the breadth of the cellular immune response as compared to native antigens alone [Yan, J., et al., Enhanced cellular immune responses elicited by an engineered HIV-1 subtype B consensus-based envelope DNA vaccine. Mol Ther, 2007. 15(2): p. 411-21; Rolland, M., et al., Reconstruction and function of ancestral center-of-tree human immunodeficiency virus type 1 proteins. J Viral, 2007. 81(16): p. 8507-14].
One method for delivering nucleic acid sequences such as plasmid DNA is the electroporation (EP) technique. The technique has been used in human clinical trials to deliver anti-cancer drugs, such as bleomycin, and in many preclinical studies on a large number of animal species.
While vaccines are often effective to immunize individuals prophylactically or therapeutically against pathogen infection or human diseases, there is a need for improved vaccines. There is a need for compositions and methods that produce an enhanced immune response. Likewise, while some immunotherapeutics are useful to modulate immune response in a patient there remains a need for improved immunotherapeutic compositions and methods.